BACKGROUND Ultrasonic motors (USM) are based on the concept of driving the rotor by a mechanical vibration excited on the stator via piezoelectric effect. USM exhibit merits such as simple structure, quick response, quiet operation, self-locking when power off, nonelectromagnetic radiation and higher position accuracy. PRINCIPAL FINDINGS A cylindrical type traveling wave ultrasonic motor usin...

Based on the development of numerical analysis techniques over the past decade, the engineer can easily model the internal flow conditions and vibration characteristics of turbomachinery. When focusing on vibration response of rotating blades, it is easy to predict the resonance frequency; however difficulty remains in the prediction of vibrational stress. The primary reasons include: The unste...

background: deficiency of attention and concentration is one of great reasons of traffic incidents and it covers between 20 to 50 percent of events due to careless and mindedness. studies show that attention and concentration are considered as one of important cognitive components in safe driving. vibration is an important physical effect in all vehicles. till now has not been any organized stu...

Accurate knowledge of the rate as well as the mechanism of excitation of the bending mode of CO2 is necessary for reliable modeling of the mesosphere–lower thermosphere (MLT) region of the atmosphere. Assuming the excitation mechanism to be thermal collisions with atomic oxygen, the rate coefficient derived from the observed 15 μm emission by space-based experiments (kATM = 6.0× 10 cms) differs...

OVER THE PAST 20-30 YEARS, substantial progress has been made in our understanding of dyspnea. We have come to the realization that dyspnea encompasses a number of distinct sensations (16) and that a diverse array of receptors in the chest wall, lungs, airways, and central nervous system may influence the quality and intensity of an individual’s respiratory sensation. In this issue, Edo and col...

The development and application of computational methods for studying molecular crystals, particularly density-functional theory (DFT), is a large and ever-growing field, driven by their numerous applications. Here we expand on our recent study of the importance of many-body van der Waals interactions in molecular crystals [A. M. Reilly and A. Tkatchenko, J. Phys. Chem. Lett. 4, 1028 (2013)], w...

We present an ab initio direct dynamics trajectory study of the hydrogen abstraction reaction: H2CO+ + CD4 --> H2COD+ + CD3, with methane excited in two different distortion modes (nu4 and nu2). The trajectory simulations were able to reproduce experimental results and for the first time show how vibrational enhancement originates in reaction of small polyatomic species. Roughly equal contribut...

This paper studies the dynamics and control of the Gough–Stewart platform for vibration control of a flexible supporting structure. The problem arises from a large radio telescope in which the astronomical equipment is mounted on a platform to be stabilized by a Gough–Stewart platform, while the base platform of the mechanism itself is carried by a vibrating cable-car that moves along flexible ...